And they’ve been increasing since 2016, according to Syracuse University's TRAC Immigration database, which monitors U.S. federal immigration enforcement.
As of now, there are 714,067 pending immigration cases, according to the database.
By comparison, there were just over 400,000 in 2014, just over 450,000 in 2015 and more than 515,000 in 2016, the most recent year for which data is available.
The courts in New York, Los Angles, San Francisco and Houston are experiencing the biggest backlogs, data show.
In response, the U.S. Justice Department sent 35 more prosecutors to the Southwestern border last month. The department’s Executive Office for Immigration Review (EOIR), which adjudicates immigration cases, also added 18 immigration judges to hear cases in person and via video conference.
The assistant U.S. attorneys are allocated along the southern border states of Texas, California, Arizona and New Mexico.
In a speech earlier this month at the EOIR, Sessions talked about a 50 percent increase in the number of U.S. immigration judges hearing cases in the coming year.
Because the Department of Justice now refers all immigration cases for prosecution, there could be a bigger increase of backlogged cases.
At an event last month, EOIR Director James McHenry said his office is always looking for ways to expiate the process but ensure due process.
There are more than 320 immigration judges around the country but Sessions has signaled that he wants to hire more to address the problem.
To that end, Congress has given the DOJ room to hire up 150 new judges, McHenry said.
But President Trump expressed a different view in his reaction to a proposal by Senate Republicans, saying that adding judges on the southwest border would be "crazy."